Fluxes and budgets of biogenic elements at the sediment-water interface of Marian Cove, King George Island

Abstract

AbstractFluxes of dissolved oxygen and nutrients and vertical fluxes of particulate organic elements were investigated in the subtidal benthic environment of Marian Cove, King George Island, Antarctica, usingin situbenthic chambers and near-bottom sediment traps. Fluxes of dissolved oxygen, ammonium, phosphate, and silicate were comparable to those measured in temperate regions. Sediment oxygen consumption was a good indicator of organic respiration and elemental efflux at the benthic boundary layer of Marian Cove, with good positive correlations with ammonia (r2= 0.67), phosphate (r2= 0.57), and the C:N:P ratio (106:11.5:1.15) in the chamber water. A positive relationship (r2= 0.58) between settling particulate organic carbon flux and chlaconcentration suggests that water column biomass and production are direct sources of settling particles. According to element budgets in summer assessed using the fluxes, Jinand the sum of Joutand Jburialwere 15.9 ± 8.1 and 22.6 ± 8.2 mmol m-2d-1for carbon, 2.02 ± 0.54 and 2.46 ± 0.82 mmol m-2d-1for nitrogen, 0.07 ± 0.03 and 0.23 ± 0.08 mmol m-2d-1for phosphorus, and 12.4 ± 2.7 and 13.5 ± 5.0 mmol m-2d-1for silicon, respectively. There was a broad balance between sediment organic input and remineralized output for carbon and nitrogen at the benthic boundary layer of Marian Cove.